Cerebellopontine angle medulloblastoma

Posterior fossa extra-axial variations of medulloblastoma: a pictorial review as a primer for radiologists

Manifestations of an atypical variant of medulloblastoma of the posterior fossa in extra-axial locations have been reported, and key questions concerning its interpretation have been raised previously. This review illustrated the clinico-radiological and histopathological features of the posterior fossa extra-axial medulloblastoma and described possible management strategies. We thoroughly reviewed all atypical anatomical locations of medulloblastoma reported within the posterior fossa and extra-axial spaces. The main characteristics of diagnostic imaging and histopathological results, primarily the distinctive radiopathological characteristics, were summarized to distinguish between intra- and extra-axial medulloblastoma, or pathologies mimicking this tumor. Most cases of posterior fossa extra-axial medulloblastoma have been reported in the cerebellopontine angle, followed by the tentorial and lateral cerebellar locations. The dural tail sign, which is commonly observed in meningioma, is rarely seen in intra- or extra-axial medulloblastoma and might be associated with other benign or malignant lesions. In addition to magnetic resonance imaging, the proposed new imaging techniques, including advances in modern neuroimaging modalities, were discussed, as potentially efficient modalities for characterizing extra-axial medulloblastoma. Radionuclide imaging and magnetic resonance perfusion imaging are practical alternatives to limit the number of differential diagnoses. We believe that medulloblastoma cases are likely under-reported because of publication bias and frequent tumors in unusual locations. Addressing these issues would help establish a more accurate understanding of this entity.

Extra-axial medulloblastoma in the cerebellar hemisphere

Extra-axial medulloblastoma is a rare phenomenon. We report a case in a 5-year-old boy who presented with nausea, vomiting, and gait disturbance. He was treated with total removal of the tumor. This is the first case of an extra-axially located medulloblastoma occurring in the cerebellar hemisphere posteriolateral to the cerebellopontine angle in Korea. Although the extra-axial occurrence of medulloblastoma is rare, it should be considered in the differential diagnosis of extra-axial lesions of the posterior fossa in children.

Review of cerebellopontine angle medulloblastoma

Cerebellopontine angle (CPA) medulloblastomas (MB) are rare lesions with few cases previously described in the literature. We report two further cases of CPA MB. The patients were a 22-year-old man and a 26-year-old woman with a mass developing in the CPA. The preoperative radiological diagnosis was vestibular schwannoma in the first case and petrosal meningioma in the second case. The patients were operated on through a retrosigmoid approach. The intraoperative findings revealed an intra-axial tumour and the histological diagnosis was classic type of MB in both cases. We review the literature and discuss pathological and radiological features and possible pathogenesis of CPA MB, underlining the necessity to consider MB in the differential diagnosis of CPA lesions.

Cerebellopointine angle medulloblastoma

Cerebellopontine angle (CPA) medulloblastoma is a rare tumour. To date, only 19 cases have been reported over a period of 8 years, we have treated 14 cases of CPA medulloblastomas. This is first and the largest series of CPA medulloblastomas reported in the world literature.

[Medulloblastoma presenting as an extra-axial tumor in the cerebellopontine angle]

Differences in the imaging characteristic of adult medulloblastomas have been reported, including involvement of lateral cerebellar hemispheres with an extra-axial appearance. We present a case report of this rare circumstance: a 40 year old man presented with a 3 weeks history of headache, morning vomiting and left hearing difficulties. Magnetic resonance imaging revealed a left cerebellopontine angle (CPA) tumor, like a well circumscribed homogeneously enhancing mass. Through a left suboccipital craniectomy the tumor was totally removed. It presented as a cerebellopontine angle tumor, like a meningioma, and not as an intra-axial tumor. Histological analysis revealed that the tumor was composed of densely packed with highly proliferative cells that produce a dense intercellular reticulin fiber network. Inmunohistochemical analysis showed positive expression to synaptophysin, specific neuronal enolase and cromogranin. Histological diagnosis was crucial to define it as a desmoplastic medulloblastoma the present case and to perform postoperative adjuvant therapy. Neurosurgeons should be aware of the possibility that a CPA tumor is of intraaxial origin, because this increase the variability on pathological diagnosis.

Medulloblastoma of the cerebellopontine angle--case report

A 21-year-old male patient presented with a rare cerebellopontine angle medulloblastoma manifesting as cerebellar and long tract involvement signs and symptoms. The clinical and radiological characteristics of the lesion were similar to extraaxial lesions of cerebellopontine angle. The histological diagnosis of the lesion was medulloblastoma. Surgery achieved partial removal and was followed by radiotherapy and chemotherapy. The patient remained well after 18 months. Medulloblastoma of the cerebellopontine angle is a relatively rare clinical entity and may occur as a dural-based extraaxial mass.